Segmental abrasive wheel



Oct. 24, 1939. PATT 2,177,550

SEGMENTAL ABRASIVE WHEEL Filed Feb. 23, 1939 4 Sheets-Sheet l n if AW Il I 14 13 1e INVENTOR. LEON A. PATT JAM/1M ATTORNEY.

0a. 24, 1939.- L. A. PATT 2,117,550

SEGMENTAL ABRASIVE WHEEL Filed Feb. 23, 1939 4 Sheets-Sheet 2 INVENTOR.LEON A. PATT BY WW ATTORNEY.

Oct. 24, 1939. L. A. PATT 2,177,550

SEGMENTAL ABRASIVE WHEEL Filed Feb. 25, 19:59 4 Sheets-Sheet s INVEM'OR.LEON A. PATT BY ale/5W ATTORNEY.

Oct. 24, 1939. 1.. A. Pm 2,177,550

SEGMENTAL ABRASIVE WHEEL Filed Feb. 23, 1939 4 Sheets-Sheet 4 J1 7. 2 1a19 in 4 1.9 a

INVENTOR. LEON A. PA'TT BY Win/M14 ATTORNEY.

Patented Oct. 24, 1939 UNITED STATES PATENTJOF'FICE ssom'rsr'. smuisrvswnsnr.

Leon A. Patt, Sanborn, N. Y assignmto The Carbornndum Company, NiagaraFalls, N. Y., a

corporation of Delaware Application February :3, 1989, sci-m No. 257,899

This invention relates'to segmental abrasive wheels and particularly towheels of this type which are used for the manufacture of wood pulp. Oneobject of the invention is to provide a simple rugged construction inwhich the amount of machining required for metal parts is small. i

The cost of a pulp wheel increases enormously with the complexity of themounting for individual segments. It is therefore desirable to restrictthe elements of the segmental mounting as far as possible to strongcylindrical elements which do not require much processing outside ofdrilling, threading. or slightmachining.

The general structure of the type of pulp wheel which is disclosed inthe present application is shown in the accompanying drawings in which:

Figure 1 is a partial sectional elevation of a portion of a segmentalpulp wheel, the section being taken in an axial plane of the wheel;

Figure 2 is a fragmentary section of the segmental pulp wheel in a planeperpendicular to the axis of rotation, the section being taken on theline 11-11 of Figure 1;

Figure 3 is a side elevation of the pulp wheel mounted on adrivingshaft;

Figure 4 is a plan view of one of the annular clamps used for each ringof segments;

Figure 5 is a section on the line V--V of Fig so ure 4; a

Figure 6 is a fragmentary enlarged view taken in an axial plane of thewheel to illustrate the character of one of the joints indicated inFigure 1;

Figure '7 shows a modification of the abrasive wheel illustrated inFigure 1; and

Figure 8 is a fragmentary section taken in the plane indicated byVIII--VI]I of Figure '1.

Referring to the drawings in detail, the segmental pulp wheel is made upof a series of abrasive segments 2 which are provided with dovetailedbases. The segments are arranged in annuli with the aid of ring clamps 3which are shaped to fit into grooves provided on opposite sides of thebase of each segment. The segmental pulp wheel is made up of a pluralityof similar abrasive annuli. To form one of the abrasive annuli thesegments for that particular annulus can be laid on a horizontal tablein correct relative positions and then provided with resilient jointfillers containing vulcanized rubher, or containing a material known inthe trade as Synthane, or containing material of similar characteristicsbetween adjacent segments. The segments and the radial joint fillers areclosely cemented together so that a substantially solid annulus isformed One of the clamping rings 3 can then be placed with the aid of asuitable temporary support inposition above the abrasive annulus,leaving a small gap for seat- I ing material which is subsequentlyintroduced between the clamping ring and the individual abrasivesegments. Studs or bolts 4 are then dropped into position throughcorresponding holes in the clamping ring and in the bases of lo theabrasive segments. The studs 4 are preferably made of approximately 34to 42 per cent nickel steel which has about the same coeflicient ofthermal expansion as the abrasive material. If this nickel steel is notused, the studs should be made of a sumciently elastic material so thatdangerous stresses will not be produced in the bases of the segments orin the studs by changes of temperature, while the studs are undertension over the range of temperature to 2 which the wheel is subjected.A seat of lead or babbitt, or of cementitlous material, is poured inbetween'th ring 3 and the segments of the abrasive annulus in thepositions indicated by the reference character ID in Figure 1. After 25the lead. babbitt or cement has hardened, the assembly is turned overand the second clamping ring for the abrasive annulus is put in positionin a similar manner, and the material for the seat I B is poured inplace. After the seat- 3 ing material has hardened; the nuts 5 aretightened to a predetermined pressure. The upper face of the abrasiveannulus can then be trimmed down in a plane which makes a small anglewith the opposite side of the annulus, if the latter 85 is to be one ofthe outside annuli. The object of this procedure is to provide biasedjoints of the type shown in Figure 3.

A second annulus is formed in a manner similar to that described for theformation of the 40 first annulus. Sheets of resilient material incombination with cement on both sides of each sheet are used to form ajoint between adjacent faces or sides of the first and second abrasiveannuli. A third annulus may be added in a simi- 45 lar manner, and so onuntil the desired width of wheel is obtained. Rods or tie bolts 6 areput through registering openings in radially inward portions of therings 3 to hold the successive abrasive annuli together when nuts I aretightened on terminal threaded portions of the tie rods. Before the tierods 6 are inserted, annular metal reinforcing rings 8 can be placed inthe positions indicated in Figure 1. These rings 8 are disposed inplanes perpendicular to l the axis of the wheel and embrace all the tierods. In the core inside the abrasive annuli other metal reinforcementsindicated by'the reference characters 3 and II can be placed asindicated in Figure 1. These can be connected with the annular clamps bymeans of reinforcing supports II. A reinforcing system of smaller radialdimensions is shown at l3 and I4 in Figure 1. Inside the last mentionedreinforcing system is positioned the wheel hub l5 and an arbor sleeveI6.

After the reinforcing systems have been placed in position along withthe hub and sleeve, the space between the arbor sleeve and the segmentalbases is filled with concrete or other suitable material, the necessaryforms being used to confine the concrete within the boundaries shown inFigure 1. The reinforcements are made of iron or steel having about thesame coemcient of expansion as the concrete.

The tie rods 6 can be made to have about the same coeflicient ofexpansion as the concrete. The inner surfaces of the abrasive segmentsare lined with a waterproofing material which forms a seat for thesegment and prevents the passage of water from the concrete into theabrasive while the concrete is setting, thus preventin radial shrinkage.

Since the coefiicient of expansion of the concrete core is greater thanthat of the abrasive segments, there is a tendency to distort the rings3 so that the radially inward portions I I (see Figure 1) are pushedfurther apart by a given rise of temperature than the radially outwardportions l8, these portions of the ring being disposed in opposite sidesof the studs 4. A distortion of the rings 3 in the direction describedis in the right direction to maintain the rings in pressure relationshipwith the reduced portions of abrasive segments as the temperatureincreases during the operation of the wheel. It has been found bycareful tests that heating of the whole wheel above room temperaturetends to distort the radially outward portions H! of the rings 3 towardthe abrasive segments 2, thus tending to clamp them even more tightly.

Some of the principal advantages of the pulp wheel constructiondescribed will be apparent from the above description.

The metallic parts are of a simple character so that little machining isrequired in the manufacture of the metal parts. A positive driving meansis provided for the abrasive segments.

In the modification illustrated in Figures 7 and 8, the studs 4 do notpass through the bases of the abrasive segments, but pass through theconcrete adjacent the bases of the segments.

A number of variations may be made in the character of the metal partsand of the joint materials without departing from the invention which isdefined within the compass of the following claims.

I claim:

1. An abrasive wheel comprising a plurality of abrasive annuli, each ofwhich contains a plurality of abrasive segments, ring clamps disposed onopposite sides of each abrasive annulus and clamped to the segmentsbymeans extending through reduced base portions of the segments, tierods which'extend through the bases of said ring clamps in a directionparallel to the axis of the wheel, and a concrete core in which said tierods and the bases of said annular clamps are embedded.

2. The abrasive wheel described in claim 1 in which metal reinforcementsembedded in the concrete extend around the tie rods in planesperpendicular to the axis of the wheel.

3. A segmental abrasive wheel comprising a plurality of abrasive annulieach of which contains a plurality of abrasive segments, a pair ofclamping rings attached to the base of each abrasive annulus, a concretesupport for the clamped annuli, and studs extending throughcorresponding openings in the clamping rings in directions parallel tothe axis of the segmental wheel, said studs having a coefficient ofexpansion substantially equal to that of the abrasive segments. .7

4. A segmental abrasive wheel comprising a plurality of abrasive annulieach of which contains a plurality of abrasive segments, a pair ofclamping rings attached to the base of each abrasive annulus, a concretesupport for the clamped annuli, and studs extending throughcorresponding openings in the clamping rings in directions parallel tothe axis of the segmental wheel, said studs being made of an elasticsteel having suflicient resilience to compensate for differences ofexpansion of the abrasive material and its support in an axialdirection.

5. An abrasive annulus comprising a plurality of segments whichareunited by means of radial joints cemented to adjacent sides of thesegments, a metal ring disposed on each side of the reduced annularbase, a concrete center for the annulus having a coefficient ofexpansion greater than that of the abrasive segments, said concretecenter extending between the radially inward parts of the metal rings tothe bases of the segments, and means extending through the radiallyoutward parts of the metal rings and through the reduced bases of thesegments for maintaining the rings in engagement with the segmentalbases as the temperature increases in the operation of theabrasive-annulus.

LEON A. PA'I'I.

